Pulsed jet riot control apparatus

ABSTRACT

Apparatus for forming pulsed jets of liquid at relatively low pressures and capable of expelling the pulsed jets over moderate distances for use as a riot control device. A compressed gas is passed to a chamber having liquid therein so that upon actuation of a quick opening valve the liquid is forced from the chamber, through an acceleration tube and out a nozzle. The quick opening valve might be positioned between the pressurized gas source and the liquid chamber, or it might be in the acceleration tube. The gas can act directly on the liquid or it can act through a piston.

[ 1 Mar. 27, 1973 [54] PULSED JET RIOT CONTROL APPARATUS [75] Inventors: James M. Hall, Gaithersburg, Md.;

Louis L. Clipp, McLean, Va.

[73] Assighee: Exotech Incorporated,Gaithersburg,

[22] Filed: Apr. 19, 1971 [21] Appl. No.1 135,235

[52] US. Cl ..239/102, 239/322 [51] Int. Cl. ..B05b l/08 [58] Field of Search ..239/l01, 102, 308, 321, 322,

Cooley ..239/601 X Schaffler ..239/172 Primary ExaminerM. Henson Wood, Jr.

- Assistant ExaminerMichael Mar AttorneyMorton, Bernard, Brown, Roberts & Sutherland [57] ABSTRACT Apparatus for forming pulsed jets of liquid at relatively low pressures and capable of expelling the pulsed jets over moderate distances for use as a riot control device. A compressed gas is passed to a chamber having liquid therein so that upon actuation of a quick opening valve the liquid is forced from the chamber, through an acceleration tube and out a nozzle. The quick opening valve might be positioned between the pressurized gas source and the liquid chamber, or it might be in the acceleration tube. The gas can act directly on the liquid or it can act through a piston.

9 Claims, 4 Drawing Figures Patentgd March 27, 1973 II i" 3 Hi m I l l I II M INVENTORS JAMES M. HALL 8 ATTORNEYS III lllll mm LOUIS L CLIPP BY W 1 PULSEI) JET RIOT CONTROL APPARATUS The present invention pertains to apparatus for forming low pressure pulsed jets of liquid. More particularly, the present invention pertains to apparatus suitable for riot control and capable of transmitting pulsed jets of liquid at relatively low pressures over distances and suitable for such uses as riot control.

One of the more effective means of riot control is the spraying of water on the rioting crowd.

The use of water as a meansfor dispersing a crowd has many advantages. The water flow is easy to control. It can be turned off and on by a solenoid actuated valve. The area is largely uneffected once the water is stopped. The spraying of the water can'be maintained in a desired direction without spraying into other areas. Water is nontoxid and so causes no lasting injury to the crowd. Water is generally readily available in large quantities and is inexpensive. Additives can be used with the water is desired.

If a continuous stream of water is used in riot control, the water spraying apparatus must be connected to a large water source. Fire hoses connected to hydrants have been utilized for this purpose; however, this restricts the area in which the water can be utilized to a relatively short radius in the vicinity of the hydrant. If the water is expelled as pulsed jets rather than in a steady stream considerably less water is required, making possible the use of a mobile vehicle which carries a reservoir of water and which can be moved from area to area as required.

The present invention is an apparatus for generating pulsed jets of liquid at relatively low pressures, for example pressures in the order of about I to about 500 p.s.i., and capable of traveling moderate distances, for example distances in the range of from about 50 feet to about I50 feet. In accordance with the present invensupply passes through valve 12 to single-shot accumulator 14 which holds enough gas for one operation of the device. The outlet of accumulator 14 is coupled by quick opening valve I6 to the upper portion of tank 18. Water from an inlet 20 is supplied through valve 22 to tank 18. Acceleration tube 24 has its inlet tank 26 within tank 18 and near the bottom of the tank. Acceleration tube 24 preferably includes a flexible portion 28 making it possible to direct water jets in any direction. Acceleration tube 24 has its outlet connected to nozzle 30 from which the water jets are discharged. Preferably, acceleration tube 24 has a diameter in the order of 3'4 of an inch upto 2 or 3 inches and nozzle 30 has an inlet diameter of the same order, a tapered outlet diameter which reduces the diameter in the order of about 74 to 1 inch and a length in the order of about to 30 inches.

Water from inlet is passed through valve 22 to tank 18 filling the tank to a level just below the tank inlet from valve 16. When it is desired to generate pulsed jets of water, quick opening valve 16 is actuated, releasing pressurized gas from accumulator 14 into tank 18. The pressurized gas acts on the water in tank 18, forcing the water through inlet 26 of acceleration tube 24. The water passes through tube 24 and out noztion, a compressed gas is passed to a chamber containing water. Upon actuation of a quick opening valve, the water is forced through an acceleration tube and out a nozzle. The quick opening valve might be positioned between the pressurized gas source and the water chamber or it might be positioned between-the water chamber and the acceleration tube with the compressed gas continuously acting upon the water. The compressed gas can either act directly on the water or can act on the water through a piston.

These and other aspects and advantages of the present invention are more apparent in the following detailed description and claims, particularly when considered in conjunction with the accompanying drawings. In the drawings:

FIG. 1 is a schematic representation of a first embodiment of apparatus in accordance with the present invention;

FIG. 2 is a schematic representation of a second embodiment of apparatus in accordance with the present invention;

FIG. 3 is a schematic representation of a third embodiment of apparatus in accordance with the present invention; and

FIG. 4 is a schematic representative of a further embodiment of apparatus in accordance with the present invention.

In accordance with the embodiment of the present invention depicted in FIG. 1, gas from a pressurized .zle 30. The decreasing internal diameter of nozzle 30 increases the water velocity with the result that a pulsed jet of water having a diameter in the order of one to two inches is discharged at a pressure in the order of to 500 p.s.i. and typically might travel a distance in the order of 50 to feet. The embodiment of FIG. 1 is preferably mounted on a vehicle, not shown, such as a truck body, os that it is easily transportable.

The apparatus of FIG. 1 can readily be assembled, for example of steel and ready made tubing. Valves suitable for use as quick opening valve 16 have been developed in conjunction with rocket propulsion systems and are capable of millisecond operation.

FIG. 2 depicts apparatus in accordance with the present invention and having pressurized gas source 32 coupled by valve 34 to accumulator 36, the outlet of which is connected to tank 38. Water inlet 40 is coupled by valve 42 to tank 38. Acceleration tube 44 has its inlet 46 adjacent the bottom of tank 38. Quick opening valve 48 intersects acceleration tube 44 between inlet46 and bent portion 50 which can be flexible. The acceleration tube continues from flexible portion 50 and has its outlet connected to nozzle 52.

The operation of the embodiment of FIG. 2 is similar to that of FIG. 1.. Gas from source 32 continuously applies pressure through accumulator 36 on the water within tank 38. When it is desired to discharge a pulsed jet, quick opening valve 48 is operated, permitting the water to pass through acceleration tube 44 to nozzle 52 from which it is discharged. Also, if desired, hydraulic pressure can be used to apply pressure on the water directly through a piston, or can be used to cock a piston which is then actuated by gas, or by other means,

' as depicted in FIG. 4.

FIG. 3 depicts a further embodiment of apparatus in accordance with the present invention. Gas from a pressurized source 54, which can include a single shot accumulator, is applied to quick opening'valve 56, the outlet of which is connected to the first end of tank 58.

Piston 60 fits snugly but slidingly within tank 58 and, if desired, can include piston ring 62 to provide a substantially fluid-tight seal. Water from an inlet 64 is applied through valve 66 to the second end of tank 58 on the side of piston 60 opposite valve 56. Acceleration tube 68, including flexible portion 70, extends from the second end of tank 58 and connects to nozzle 72. when it is desired to generate a pulsed jet of water with the apparatus of FIG. 3, water from inlet 64 is passed through valve 66 to fill tank 58. Quick opening valve 56 is then actuated, and pressurized gas from source 54 moves piston 60, expelling the water through acceleration tube 68 to nozzle 72 from which it is discharged. Valve 74 is then opened to release the gas from tank 60, permitting piston 60 to return to the initial position under pressure of water from inlet 64 or gravity. If desired, valve 74 can return this discharged gas to source 54.

It is thus seen that in accordance with the present invention a simple, economical and flexible apparatus is provided for generating pulsed jets of liquid at relatively low pressures. Although the invention has been described with reference to preferred embodiments, numerous rearrangements and modifications can be made and still the result would be within the scope of the invention.

What is claimed is:

1. Riot Control apparatus utilizing pulsed jets of liquid comprising:

an enclosed liquid reservoir having a first valved inlet adapted for connection to a source of liquid and having a second inlet;

a gas supply line coupled to said second inlet and adapted for connection to a pressurized gas source;

an acceleration tube having an outlet and having an inlet within said enclosed liquid reservoir;

a nozzle connected to said acceleration tube outlet;

and 1 quick opening valve means coupled to said enclosed liquid reservoir and capable ofactuation to expel liquid, under pressure of gas from said gas supply line, through said acceleration tube and out said nozzle as a pulsed liquid jet.

2. Apparatus as claimed in claim 1 in which said quick opening valve couples said gas supply line with said enclosed liquid reservoir second inlet so that upon actuation of said quick opening valve pressurized gas from said gas supply line applies pressure to liquid within said enclosed liquid reservoir to expel liquid through said acceleration tube and out said nozzle as a pulsed liquid jet.

3. Apparatus as claimed in claim 1 in which said quick opening valve is within said acceleration tube so that upon actuation of said quick opening valve liquid within said enclosed liquid reservoir is expelled through said acceleration tube and out said nozzle as a pulsed liquid jet under pressure of gas from said gas supply line.

4. Apparatus as claimed in claim 1 further comprising a piston within said enclosed liquid reservoir and intermediate the first valved inlet and the second inlet so that upon actuation of the quick opening valve gas from the gas supply line applies pressure through the piston to expel liquid from said enclosed liquid reservoir through said acceleration tube and out said nozzle as a pulsed liquid jet.

5. Apparatus as claimed in claim 2 further comprising a piston within said enclosed liquid reservoir and intermediate the first valved inlet and the second inlet so that upon actuation of the quick opening valve gas from the gas supply line applies pressure through the piston to expel liquid from said enclosed liquid reservoir through said acceleration tube and out said nozzle as a pulsed liquid jet.

6. Apparatus as claimed in claim 3 further comprising a piston within said enclosed liquid reservoir and intermediate the first valved inlet and the second inlet so that upon actuation of the quick opening valve gas from the gas supply line applies pressure through the piston to expel liquid from said enclosed liquid reserv voir through said acceleration tube and out said nozzle asa pulsed liquid jet.

7. Apparatus as claimed in claim 1 in which said gas supply line includes a gas accumulator for accumulating gas for one operation of said apparatus.

8. Apparatus as claimed in claim 1 in which said first valved inlet and said second inlet each communicate with said enclosed liquid reservoir adjacent the top thereof and in which'said acceleration tube inlet is within said enclosed liquid reservoir adjacent the bottom thereof to permit entry of liquid into said reservoir through said first valved inlet and application of pressurized gas through said second inlet onto liquid within said enclosed liquid reservoir to force liquid within said reservoir out said acceleration tube.

9. Apparatus as claimed in claim 4 in which said valved inlet communicates with said enclosed liquid reservoir adjacent the top thereof and said second inlet communicates with said enclosed liquid reservoir adjacent the bottom thereof to permit entry of liquid into said reservoir on the first side of said piston and entry of pressurized gas into said reservoir on the second side of said piston to raise said piston and expel liquid out said acceleration tube. 

1. Riot Control apparatus utilizing pulsed jets of liquid comprising: an enclosed liquid reservoir having a first valved inlet adapted for connection to a source of liquid and having a second inlet; a gas supply line coupled to said second inlet and adapted for connection to a pressurized gas source; an acceleration tube having an outlet and having an inlet within said enclosed liquid reservoir; a nozzle connected to said acceleration tube outlet; and quick opening valve means coupled to said enclosed liquid reservoir and capable of actuation to expel liquid, under pressure of gas from said gas supply line, through said acceleration tube and out said nozzle as a pulsed liquid jet.
 2. Apparatus as claimed in claim 1 in which said quick opening valve couples said gas supply line with said enclosed liquid reservoir second inlet so that upon actuation of said quick opening valve pressurized gas from said gas supply line applies pressure to liquid within said enclosed liquid reservoir to expel liquid through said acceleration tube and out said nozzle as a pulsed liquid jet.
 3. Apparatus as claimed in claim 1 in which said quick opening valve is within said acceleration tube so that upon actuation of said quick opening valve liquid within said enclosed liquid reservoir is expelled through said acceleration tube and out said nozzle as a pulsed liquid jet under pressure of gas from said gas supply line.
 4. Apparatus as claimed in claim 1 further comprising a piston within said enclosed liquid reservoir and intermediate the first valved inlet and the second inlet so that upon actuation of the quick opening valve gas from the gas supply line applies pressure through the piston to expel liquid from said enclosed liquid reservoir through said acceleration tube and out said nozzle as a pulsed liquid jet.
 5. Apparatus as claimed in claim 2 further comprising a piston within said enclosed liquid reservoir and intermediate the first valved inlet and the second inlet so that upon actuation of the quick opening valve gas from the gas supply line applies pressure through the piston to expel liquid from said enclosed liquid reservoir through said acceleration tube and out said nozzle as a pulsed liquid jet.
 6. Apparatus as claimed in claim 3 further comprising a piston within said enclosed liquid reservoir and intermediate the first valved inlet and the second inlet so that upon actuation of the quick opening valve gas from the gas supply line applies pressure through the piston to expel liquid from said enclosed liquid reservoir through said acceleration tube and out said nozzle as a pulsed liquid jet.
 7. Apparatus as claimed in claim 1 in which said gas supply line includes a gas accumulator for accUmulating gas for one operation of said apparatus.
 8. Apparatus as claimed in claim 1 in which said first valved inlet and said second inlet each communicate with said enclosed liquid reservoir adjacent the top thereof and in which said acceleration tube inlet is within said enclosed liquid reservoir adjacent the bottom thereof to permit entry of liquid into said reservoir through said first valved inlet and application of pressurized gas through said second inlet onto liquid within said enclosed liquid reservoir to force liquid within said reservoir out said acceleration tube.
 9. Apparatus as claimed in claim 4 in which said valved inlet communicates with said enclosed liquid reservoir adjacent the top thereof and said second inlet communicates with said enclosed liquid reservoir adjacent the bottom thereof to permit entry of liquid into said reservoir on the first side of said piston and entry of pressurized gas into said reservoir on the second side of said piston to raise said piston and expel liquid out said acceleration tube. 